Ceramic slab forming process and apparatus



June l2, 1934. E, R POWELL CERAMIC SLAB FORMING PROCESS AND APPARATUS Filed March` 13. 1931 4/7 o s l l u l t I V raaf-...2-

FIBv l Z0 a 20 zo INVENTOR.l [ws/mfp i?, Fou/fu..

ATTORNEY:

Patented June 12, 1934 UNITEDfsTA 1,9s3,ozs t CERAMIC sinn romvmvd'raocnss AND AnA'rUs APP Edward R. Powell, Alexandria, Ind. AApplication March 1 3, 1931, Serial. No. 522,272

1 2 Claims. (Cl. 25.-142) This invention relates to the manufacture'of ceramic slabs of considerable size so that'they are suitablel for structural purposes.

The chief object of this invention is to produce by expansive burning, a structural unitl or slab which has considerable thickness or depth,`whereA by the unit has suicientbody to resist crushing when incorporated in a structure such as a side wall, which is relatively light, which' may have a glazed surface for outside exposure, whichA has a porous or expanded body for strength and insulation and acoustical properties, andy which may be strengthened when and where desired by the addition of suitable reenforcement.

The chief feature'of this invention consistsl in supplying, ordinarily, crushed and sizedl material capablel of expansive burning toa support and subjecting the material to the vnecessary temperature to secure such so-calledl expansive burning, then supplying particularly to the low places of the resultant rough and unevenslab finer mate- .rial in an amount at least suiiicient to form when similarly burned' a substantially level surface.V

Since the expansion occurs in a spheroidal manner, and since the finer material subsequently applied to the initial material fails to completely iill all voids therein,l a lightweight ceramicfslab is finally obtained. However', due to the expansive burning the successivel layer is not only formed as such, but is likewise simultaneously fusibly secured to the previous layer.

Another feature of the process consists in its ready adaptation to the production of a metallic reenforced slab. This is accomplished by first supplying a layer vof material capable of expan. sive burning, then layingr thereon the metallic re.A enforcement, such as expanded metal, wire fencing, .Wire mesh or heavy screeningcompletely 'covering same to protect it, and with additional material, and then leveling as previously indicated.

Fence wire of No. 12 or 14 gage has been found suitable. When single stage formation. is desired, the reenforcement may be coated with clay slip or embedded in a clay core which protects the reenforcement during the burning.

In certain instances, the clay protected reenforcem'ent may be provided with an easily fusible clay slip. This fusible slip will materiallyl increase the bond between the reenforcement and the expansive burnable material. The fusible.. slip will likewise prevent' fiaking of the initial, slip. This latter is usually partially dried, 1be fore the fusible slip is applied thereto, which apI plication may be by dipping or the like.

- ent densities.A

A'The sockets yma reenforcement.

When lthe slab or portions thereof -are to be Another feature of the invention consists in the formation of successivelayers of expanded material which may be of' like density or'diier- Ithas been determined'that if the material --capableof expansive burning is 60 moister than other like material, the moister ma- -terial willhave larger cells therein than the other.

' Another feature of the invention consists in the formation of a layer ofceramic material from a lplurality of spaced or slightly isolated portions 65 -of material, capable of expansive burning, -then expanding withvheat the particles into bonded contact with adjacent particles toV form a single layer of ceramic material.

Whenever the local clay utilized doesnot have naturally the expansivevburningproperty, there may be added to it a small portion of gas forming material, such as dolomite.

.By judicious grading of material, judicious positioningv of the same, or both, undue irregularity or roughness of surface in the 'formation ofthe 'slab may bevmaterially reduced or substantially prevented.

Likewise, the completed slab-while hot or warm-may be pressed at and. even by av press vor rolls. When the ware is desired for interior surfacing, such as acoustical work,'the reenforcement may be omitted, and preferably thenatural'suriaceis dressed off to expose the porous interior. Dressing the slab can be accomplished byacarborundum saw, and the trim .if sized properlyv can be used as aggregate.

The respective slabs-may be tongue and grooved forinterlocking association when laid up and the edges, when slab is used for acoustical purposes, maybe beveled for neatness of appearance.

The slabs may be made in large sizes vand'then reduced, for example, slabs may be two feet by three feet in yarea-and from two andone-half to four or so inches in depth. These slabsthen may be reduced to brick oi' block'size if desired, and by saws or the like. The slab size mentioned is one that lends itself readily to reduction but more especially lends itself to initial production as hereinafter set forth.

When interlocking is desired, each slab may be 4provided with sockets in the form of embedded pipe, sockets of adjacent slabs registering to receive connecting dowels, as illustrated in Fig. 7.

y be apart of'or attached to the used for certain types of interiors and in general for all exterior work, glaze forming material isV voids-see Fig. 9.

usual surface value, it has r may beused.

mineral yeast (acid and. dolomite) with the clay `and drying the slurry rapidly in a rotary drier.

applied to the upper surface of the slabin its formation. The material itself or the finer particles, or the glaze forming material may include any of the usual ceramic coloring materials, such as oxides.

When laying up the units, the rough edges and the vlike expose porosities which easily are bonded together by most mortars, althoughv preferably a waterproof mortar should be employed.

For acoustical purposes, the more porous the exposed surface is, the greater the acoustical value. To increase the acoustical effects over the beenfound desirable to modify the surface from a vesicular condition-- see Fig. 8-to a vreentrant formsee Fig. 9. The vesicular form is more acceptable for use in general insulation and particularly Y cold storage installation. y l

To form a certain percentage of reentrant openings-in the slab, a preexpanded raw material .This may be made by mixing a The aggregate lthus formed should be over expanded. vThat is, most of the bubbles should break,.leaving an intercommunicating system of This aggregate in nearly-dry condition is further expanded in the reverbera- 'f tory furnace and built up into expansively burned slabs. When such a materialis to be usedfor acoustical work, the outer glaze should be dressed off to expose the porous interior. If any glaze'is used, it must be spattered and being careful i not to cover more than about (iO-'10% of the sur- I substantially completed form.

face, and the E30-40% for the sound.

The full nature ofthe invention will be understood fromy the accompanying drawing and the following description and claims:-

In the drawing, Fig. 1 is a diagrammatic side elevational view of the first-step of the process,

showing the arrangement provided for sectional formation.

Fig. 2 is a similar view of the same material after having been expansively burned and .illustrates the result after the second step of the process has been performed.

Fig. 3 is a similar view illustrating the third step of the process.

Fig. 4 is a similar view of the process. y

Fig. 5 is a sectional view of the slab sections in showing the fourth step Fig. 6 is a longitudinal sectional view through one form of the reverberatory furnace suitable for performing the process and producing a f ceramic slab.

Fig. 7 is a central sectional view `through a reinforced and socketed type of ceramic slab,.

embodying the invention.

Fig. 8 is an enlarged sectional view through a vesicular form of slab .I

Fig. 9 is a similar view of a reentrant form of slab.

In Figs. 1 to 5 inclusive, of the drawing, there is illustrated the successive steps of the process hereinbefore set forth in considerable detail.

In Fig. 1, 20 indicates the successive conveyor flights which, during the formation -of the slab, are positioned in substantially abuttingv relation. 19 indicates the' particles of material positioned thereon and which, when expansively burned, form the slab 18. The dotted line indicated at 21 shows the oscillatory extent of travel `to which the flights are subjected for parting the slabs as should provide passage ways 'level units, there is produced the finally finished product as indicated at l5 in Fig. 5.

In Fig. 6 there is illustrated-diagrammatically, a suitableform'of apparatus for carrying out the process and producing the product of this invention. In said gure, 40 indicates an upper wall of a reverberatory furnace having an air inlet 41 at one end in which is mounted a ame jet nozzle 42, which may be of the oil or gas or powdered fuel type. The llame 43 therefrom discharges longitudinally into the furnace and the products of combustion pass out at the opposite end through the stack 44. An endless conveyor 45 in thefurnace includes a plurality of refractory flights 20 suitably mounted on spaced chain links 46. The chains thereofv are asso#- ciated with sprocket wheels 4'7 vatopposite 'ends of the elongated horizontal reverberatory furnace. The lupper run of the conveyor is supported uponsupporting guide rails 48, which, as indicated at 49, are offset so that the conveyor has an up and down movement at the portion of its travel corresponding to the saw-tooth or equivalent arrangement 49 of the supporting rail or track-way 48. This movement is shown exaggerated in Fig. 6 for the sake of clearaness. Power is preferably applied to the sprocket wheel 47 at the product inlet end of the furnace so that the conveyor links 46 `will actually conform to the offset portions of the track-way 48, so `that in the passage'of the upper run of the conveyor, each flight will oscillate as shown by the dotted line indicated at 21 in Fig. 2..

There is conventionally illustrated at 50, a reciprocating carriage .which reciprocates on the transverse track-ways 51 and said carriage 50 is adapted to discharge sand or the like through the nozzle 52 to the upper surface of the upper :run of the conveyor. AThis sand, or the like, protects the conveyor flights from oxidization and the intense heat of the furnace. It also prevents sticking of the ware to the upper surface of the flights. Y.

A si-milarly transversely reciprocating carriage is indicated at 53 and is transversely movable on the track-ways 54 and the spout 55 is adapted to discharge large particles of considerable size and suitably graded, if desired', on to the upper surface of the upperrun of the conveyor flights and to the' desired depth, said spout having a suitable control valve 56 for regulating the amountof discharge. Ther rate of travel of the lconveyor is determined by the rate of burning,

be inserted in the opening 60 through 'the side or just as it isrbeginning'to burn; yand then the reinforced Ware' immediately,A thereafter passes beneath another outlet v61 communicating with carriage 62, transversely movable onwtracks 63,

i whereby additional material is supplied to the expansive burning. Agitation, or rather oscillation, of the flights beneath the dischargeoutlet 61 also will cause the finer material to settle automatically in the lower portions of the upper' surface of the slab previously formed and thus automatic leveling of the second layer of material is obtained so that upon subsequent burning, the slab surface is leveled.

There is illustrated a carriage transversely movable upon track '71 and having a spout 72. This carriage is adapted to supply to the slab theretofore formed, a surface or coating material for applying a colored or uncolored glaze or merely a color coating.

In certain forms of the invention, the material supplied by one or more of the carriages, forms a vesicular structure when burned and one or more of the other carriagesmay supply material which is capable of reentrant formation when burned. The amount supplied by each carriage, of course, may be regulated by controlling the dischargetherefrom. The means for replenishing the supply in the carriage is not illustrated, since such apparatus may be of many different characters.

After'the ware has been expansively burned and formed in separated unit formation upon the upper run of the conveyor, one slab to each flight, the conveyor discharges the slab, which is herein indicated by the numeral 80, and to a suitable transfer mechanism 81 in the'form of supporting rolls, or the like, and the same discharges 'the slab to a suitable pressing or forming means 82. the aforesaid being vmerely a conventional illustration of this station in the operation that occurs there.

In Fig. '7 of the drawing there is illustrated reinforced interlocking ware and herein 90 indicates the sab, 91 the reinforcement and mounted in the slab and suitably secured to the reinforcement is a pipe portion 92 forming a socket. Sockets in adjacent members 90 register with each other and a dowel 93 may be mounted in one socket and thus receivable by the other socket 1, for anchoring the two adjacent slabs together.

The physical finishing of the surface of the slabs formed, as hereinbefore specified, may be by any one of the methods as set forth more specifically in the first portion of the description.

The invention claimed is:-

1. The process of forming a light weight ceramic slab comprising supplying material capabe of expansive burning to a supporting surface, expansively burning same, supplying additional material to the lower portions of the upper uneven surface thereof, and expansively burning same to even up the upper surface of the resultant slab.

2. The process of forming a light weight ceramic slab of appreciable depth comprising supy V 1,963,029 wall of the furnace and positioned upon the ex'-, pansively burned material' prior to its burning.

vply-ing toi-af supporting ysurfaceffv larga particles of material capa-ble'of-,expansiv vbll-` V1195, when burning same,.gthen applying srr yller' particles Of similar lmaterial to the iowerportions of the upper surface of the heat"exp ande d fmaterial,

vand then burning,saidfsmallerparticles to even .unibe upper surfaced; thefslab- 3. The process of forming a reenforced light` weight ceramic slab comprising coating with a protective clay slip metallic reenforcement, associating the same with material capable of expansive burning in the desired relation, and then burning the material for forming the reenforced ceramic slab with the reenforcement incluvded therein.

4. The process of forming a light-weight ceramic slab having high acoustical and insulating properties comprising supplying to a supporting surface material capable of expansive burning and other material having reentrant porosity when burned, burning said materials to form a slab and removing a surface layer to expose the resulting porous interior as a porous surface. f

5. The process of forming a light weight ce- 1 ramic slab having high acoustical and insulating properties comprising supplying to a supporting surface particles of material capable of expansive burning and when burned forming a vesicular construction, burning same, then applying 1 thereto similar material but capable when burned of forming a reentrant construction, burning same, and then forming the outer surface by removal of all o1' the major portions of exposed surface area of the upper surface for exposing 1 the reentrant formation for acoustical purposes.

6. A furnace of the character described, including in combination an endless articulated conveyor having a plurality of substantially abutting plates for supporting expansively burning 1 material thereon, means for supplying material to the upper run and surface of said plates, means for causing the burning inv the furnace, and means associated with the upper run of said conto tilt relative to the next adjacent plate.

7. The process of forming a light ceramic slab having acoustical and heat insulating properties comprising forming a vesicular ceramic mass with an included aggregate having reentrant cavities, 1 and then dressing one surface of the slab to expose the cavities.

8. A process for forming an expanded slab having insulating and acoustical properties compris- -veyor for causing each plate during the burning ing supplying to a supporting surface material capable of expansive burning and other material having reentrant porosity when burned, burning sai'd material to form a slab and dressing to desired size and shape.

9. A process for forming insulating and acoustical slabs comprising cementing by fusion a combination of expanded aggregate having reentrant cavities and other material capable of expansive burning, the cementing occurring during aggregate travel accompanied by a separation'nto units during the travel. p

l0. Apparatus for forming expanded slabs including in combination a heating compartment, relatively rigid abutting conveyor elementsadapted to pass through a heating compartment, and

feeding means adapted to deposit raw material onto said elements while in the heating compartment, the motion of said elements being governed A 11. A process for forming an expanded slab having insulating and acoustical properties comprising cementing by fusion a combination of material which is capable of expansive burning 5 and material which has beenexpanded Ain wet plastic condition.

12. A process for forming anexpanded slaby having insulating and acoustical'properties comals4 prising combining ktwo materialspone capable of-l expansive .burning and the other which has been lexpanded in a wet plastic condition embedding therein a metal. reenrorce'ment and then cementing the materials, and 'the reenforcement tovf 

